P870DM2_DM3 QTJ1 stock/max TDP results

[JamieTheAnything]

well uh
This thing clocks high and also loves wattage.


4.3ish all core with the fans blaring at 100% got me this score on CB15

[JamieTheAnything]

If anyone has tips to upgrade the VRM and cpu cooling for the PM870 DM2_DM3 with the dual GPU vapor chamber, please reachout, Ive only gotten around 75 watts sustained before the VRM thermals caused the CPU to throttle under constant load. If you're able to help out please do.

[1610ftw]

Are you sure it is the VRM thermals? CPU temperature as per throttlestop still in check?

 

You could try new thermal pads or if you feel ambitious some higher end thermal putty to better cool the VRM's like here Upsiren UTP-8 or something similar.

Here is a good starting point for reading about thermal putty:

Snarks Domain - YouTube

 

Also is the power consumption with substantial undervolting?

Seems awfully high for 4.5Ghz with CB R15, should be more like 120 to 135W

 

 

 

[JamieTheAnything]

On 3/4/2025 at 1:54 PM, 1610ftw said:

Are you sure it is the VRM thermals? CPU temperature as per throttlestop still in check?

 

You could try new thermal pads or if you feel ambitious some higher end thermal putty to better cool the VRM's like here Upsiren UTP-8 or something similar.

Here is a good starting point for reading about thermal putty:

Snarks Domain - YouTube

 

Also is the power consumption with substantial undervolting?

Seems awfully high for 4.5Ghz with CB R15, should be more like 120 to 135W

 

 

 

Yes actually this was with -.125 undervolt on the cpu.

The typical behaviour is that it hits all core 4.5, the cpu heats up to around 90, pulls 130-140 watts, then it reels back to around 4.3 ghz all core. However with that it keeps itself cool under 100C after about 2-3 mins the VRM begins to throttle after pulling around 80-90 watts causing it to drop to 3.7-3.5-3.4-3.2 Ghz with the vrms throttling the cpu.

My plan is to upgrade to the TM dual heat sink, heat sink. and to modify the vapor chamber dual gpu heatsink to fit.

[1610ftw]

That is unfortunate about the power consumption, looks like a bad bin. There are 9980HK and 9900K that only pull something between 110 and 125W at 4.5 GHz which of course would be rather helpful in your case. You may want to downscale your all core speed to something like maybe 4.0 GHz for now and then go with higher speeds only for 6, 4 and 2 cores, something like for example 4.0, 4.5, 4.8 and 5.0.

 

The DM models are not that well suited for higher power draws as they were only intended to be used with 4 Core CPUs and from what I recall @Prema did not want to incorporate support for the 8 core CPUs in his Prema bios for the DM models because of this, only for 6 cores. 

 

I would still see it as a very good idea to try and improve cooling in order to sustain more than 80 or 90W but I am not sure that even with proper cooling you can expect to sustain a constant load without long term issues due to weak VRMs. It is a bit like using a 110 power supply when you laptop constantly draws 150W - cooling will only get you so far.

[JamieTheAnything]

10 hours ago, 1610ftw said:

That is unfortunate about the power consumption, looks like a bad bin. There are 9980HK and 9900K that only pull something between 110 and 125W at 4.5 GHz which of course would be rather helpful in your case. You may want to downscale your all core speed to something like maybe 4.0 GHz for now and then go with higher speeds only for 6, 4 and 2 cores, something like for example 4.0, 4.5, 4.8 and 5.0.

 

The DM models are not that well suited for higher power draws as they were only intended to be used with 4 Core CPUs and from what I recall @Prema did not want to incorporate support for the 8 core CPUs in his Prema bios for the DM models because of this, only for 6 cores. 

 

I would still see it as a very good idea to try and improve cooling in order to sustain more than 80 or 90W but I am not sure that even with proper cooling you can expect to sustain a constant load without long term issues due to weak VRMs. It is a bit like using a 110 power supply when you laptop constantly draws 150W - cooling will only get you so far.

I did some more testing and it turns out the VRM's are good up until around 100 Amps of current before they end up overheating. However hopefully once the new TM heatsink arrives (and the corrisponding modding) I will be able to go through and bump it up thanks to the beefier heatsink. *as far as I know that heatsink is the best one for this platform as far as I can recall.


This chip was still an absolute steal compared to the 9900k/s here in the US
250+$ vs 69 dollars. Both wouldve needed the same bios mod. 
In any case I think it was a very worthwhile upgrade before I come up with a feasable reason to buy a 3080 for this laptop. 

The following screenshots are after i finally tweaked it to be stable and not have the VRM's overheat.

Average clockspeed was around 3.6 Ghz all core and a 100 amp limit. Total wattage sitting around 72 watts for over 10 minutes. 

 

[1610ftw]

Yes, the prices for these chips can be great. Have you considered getting another one to see if it needs less power?

 

That benchmark is rather bad but let's see how much higher you can go once you have the new heatsink and some good TIM.

[1610ftw]

OK, I checked a 9900KS that I have here at the moment which is not that efficient and it needs about 125W when starting an all core 4.5GHz Cinebench R23.

You may want to check what your chip needs. I always use the watt number that the chip stabilizes to in Throttlestop as that is the number that is not inflated by the chip getting hotter over time so it takes out the variable of cooling.

 

[JamieTheAnything]

Additional notes, I was able to undervolt it a bit more - ~.135-ish and even wound up getting over 1800 in CB15 with an all core 4.3 Ghz. However The man Caveat being that the VRM's can only last a couple of runs going at 100-ish watts before it ends up throttling down due to the heat of the VRM's. The CPU is fine at around the upper 80's, however I've narrowed it down to the VRM's cooling as being the primary limiting factor. 

 

[JamieTheAnything]

Additional notes, If you want a way to run this in the meantime while awaiting for the new CPU heatsink, downclocking the all core max to 3.6 Ghz helps. I've tested this with the stock CPU heatsink and it will perform just fine.

However I hope I can get a consistant 4Ghz or even 4.2 Ghz all core once the new heatsink can actually cool down the VRMs.


Will report back on results!

[JamieTheAnything]

As a side note when it comes to CPU thermals themselves, As it turns out 4.2Ghz only needs roughly 97-102 Watts in order to run. And the CPU cooler contends well with it. 4.3 is 115, and 4.4 is not doable since it's reaching over 125+ watts, as far as I could test 4.5 all core is roughly 145 Watts. However I couldnt test it for more then a couple of seconds before the CPU was overheating and throttling.

 

[1610ftw]

Reading you power consumption numbers made me check the 9980HK in my MSI GT75.

 

Here is what it pulls at the beginning of a CB R15 run, 4.7 GHz seems to be the sweet spot:

 

4.3 GHz:  96 watt

4.5 GHz: 112 watt

4.7 GHz: 119 watt

4.8 GHz: 129 watt

4.9 GHz: 141 watt

 

The 4.9Ghz CB R15 finishes at a max of 147 watt with a max temperature of 87C and a score of 2134 

 

As I said previously you may want to try another sample of the QJT1 as this looks like some really bad 9880H style efficiency in a system that would really benefit from an above average CPU.